Early screening for critical congenital heart defects in asymptomatic newborns in Mazovia province: experience of the POLKARD pulse oximetry programme 2006-2008 in Poland

Background: Early diagnosis of critical congenital heart defects (CCHD) may be missed both during prenatal echocardiography and the short stay in the neonatal nursery, leading to circulatory collapse or death of the newborn before readmission to hospital. Aim: To assess the usefulness of pulse oximetry as a screening test in early diagnosis of CCHD in newborns. Methods: A prospective screening pulse oximetry test was conducted in 51 neonatal units in the Mazovia province of Poland as part of the POLKARD 2006-2008 programme between 16 January, 2007 and 31 January, 2008. Newborns with no circulatory symptoms or coexisting diseases, and no prenatal diagnosis, were enrolled. The test was performed between the 2nd and 24th hours of life in stable newborns. A double arterial oxygen saturation (SpO(2)) reading < 95% on a lower extremity led to cardiovascular evaluation and echocardiography. Results: From a population of 52,993 newborns (14.2% of births in Poland), a group of 51,698 asymptomatic infants was isolated. CCHD was diagnosed solely by pulse oximetry in 15 newborns, which constituted 18.3% of all CCHD; 14 (0.026%) false positives were obtained and there were four false negative results. The sensitivity of the test was 78.9% and specificity 99.9%. The positive predictive value was 51.7% and negative 99.9%. Conclusions: Pulse oximetry fulfilling the screening test criteria, performed on a large population of newborns in Poland, proved useful in supporting prenatal diagnostics and postnatal physical examination in the early detection of initially asymptomatic CCHD. Good sensitivity and specificity results of the pulse oximetry test have allowed it to be recommended for use in neonatal units nationwide.